Magnetic separator



, Sept. 1, 1936;

E. .GRO SSENBACHER MAGNETIC SEPARATOR 'Filed Dec. 11-, 1935 2Sheets-Sheet 1 ENTOR Sept. 1, 1936.

E. GROSSENBACHER MAGNET I C SEPARATOR Filed Dec. 11, 1935 2 Sheets-Sheet2 INVENTOR [IQ/VEST Geasss/vsacm e BY a W ATTORNEYS Patented Sept. 1,1936 TATES ATENT OFFICE 3 Claims.

'The." invention relates to magnetic separators designed primarily forremoving stray pieces of iron, steel or other substances responsive tomagnetism.from.masses of material, for instance in the. treatment of thelatter during manufacturing processes, and has for its object to providea novel type of magnetic separator adapted to operatev with a maximum ofefl'iciency and to positively remove. the stray pieces of iron, steel orother substances responsive to magnetic influence from the material andto hold the same in separated relation to said material for convenientdisposal at periodic intervals. Other more specific objects will appearfrom the description hereinafter and'the features of novelty will bepointed out'in the claims,

In the accompanying drawings, which, without defining the limits of myinvention illustrate an example thereof embodied: in a cane crushingapparatus, Fig. l is a fragmentary vertical section of a cane crushingapparatus equipped with my novel magnetic separator; Fig. 2 is a sectionon the line 2-2 of Fig. l with portions of the apparatus omitted forpurpose ofclarity; Fig. 3 is avertica1 view, partly in section, of themagnetic separator in a form designed specially for use in cane crushingapparatus; Fig. 4 is a plan View of the magnetic separator, partly insection, showing'the disposition of the magnetic coils therein; Fig.5-is a vertical section on the line 5-5 of Fig. 3 Fig. 6 is an enlargeddetail View showing the magnetic separator and a section of the lowercrusher roll of the cane crushing apparatus, and Fig. 7 is a detailedperspective view of the specially designed magnet cores which form anessential part'of my invention.

For convenience ofdescription the novel magnetic separator has beenillustrated in combination with a cane crushing apparatus for which -itis particularly adapted, it being understood however that the novelseparator is equally well adapted-for other apparatus and machines inwhich corresponding problems are developed and that accordingly theselected illustration is not i to be construed as defining the limits ofthe invention.

Referring more particularly to Figs. 1 and 2 of the drawings which showparts of a conventional cane crushing apparatus, 10 represents the usualsupporting frame on which the customary crushing rolls I l and [2 aremounted in any well-known way forrotation in the direction of the arrowsin Fig. l. The rolls H and I2 in practice are relatively widely set andmay be rotatably actuated by the usual gearsl3 and preferably are eachthe crushed cane'is passed, said rolls 15 being 10-- journalled on theframe lit and operated, for-in.- stance in the direction of the arrowsin Fig. 1, in any conventional manner.

In its illustrated form the novel magnetic separator includes a scrapertip l9, preferably mag- 1 netized as hereinafter set forth and havingits free edge in: surface engagement with the lower crushing roll'l2; inthe preferred arrangement saidfree edge of the scraper tip I9 isprovided withribsor grooves adapted to accommodate and fit the ribs orgrooves M of said roll [2. As shown in Figs; 1 and 6 the scraper tip l9extends from the roll I2at a downward inclination and forms an extensionof a correspondingly inclined guide member 20 of non-magnetic materialprovided on its upper surface with a non-magnetic cover-plate 2|preferably made of an abrasion resisting material and fixed in place,for instance, by means of bolts 22 which may also serve, as ,shown, tofasten the scraper tip l9 to the guide member 202 The latter is carriedby and forms part of a non-magnetic bar 23 recessed at its lower portionas indicated at 24 for the purpose to be more fully set forthhereinafter. As shown in Figs. 3' and' 5 the non-magnetic bar 23 and itsassociated elements are supported .in a yoke consisting of a base-plate25 of magnetic material and endmembers 26, the latter being providedwith trunnions 21 whereby the scrapertip Hi, the non-magnetic guide.member 20 and the elements associated therewith are pivotally mounted insuitable bearings 28 in the frame I 0 the nonmagnetic bar 23. may, befastened to the baseplate 25' by screws29. In order to enable thescraper'tip Is to be properly adjusted with respect to the crushing roll[2, any suitable means may be provided as exemplified for instance bythe levers 30 keyed to the ends of the trunnions 2-1, and turn-buckles31 pivotally connected with the levers 30 andithe frame I0 as shown inFig. l.

The arrangement being describedmay further include a chute 32conveniently supported in the frame lil and'slopingdownwardly from apoint nearthemagnetic separator to a point adjacent the surface of oneof the mill rolls It as illustrated in Fig. 1.

In the illustrated example, the magnetic separator includes pole shoes33 extending outward- 5 ly and upwardly from an edge of the magneticbase-plate 25 at spaced intervals as shown in l Figs. 3, 4, 5 and 7. Inaddition, specially designed magnetic cores 3d are provided and includeupright lower sections a, upright upper sections b, and intermediatehorizontal sections 0 as shown in Fig. 7. The lower sections a of thecores 34 are in engagement with the magnetic base-plate 25 to which theyare secured by iron bolts 35 whereby said base-plate 25 and cores 34 areheld in magnetic contact with each other; the upper sections 1) and thehorizontal sections 0 of the cores 3 3 are cast into'the inclined member253 made ofv non-magnetic mate rial such as for instance bronze, thearrangement being such that the free end faces of the sectionsI b. and.c areinclined and lie sub'stane tially ,flush with the outer,..surfa ce.of the inclined guide memberHZU in spaced relation to. .eachothertransversely oi. said member Zllas 1 shownin Fig. '5. At points .-inregistry with the end faces of the. horizontal. sections 0 of they cores34, the member 261s provided with angle plates 36 of magnetic materialfittedinto suitable recesses 2i, with which the non-magnetic coverw,;plate. 2l is provided as. shown in Fig. 4; the angle platestfi, arefurther fitted over, the delivery .edge of the guide member-J8 insurface contact with the end faces of the core. sections 0 and with thelower sections a of, the cores Mas shownin Figs. 45s .f nd 5-.,..I he.ll s ra exam ethe coils 31 are all wound in the same direction andare ne d h argu ent le ic v n any e e iqnelman r cr rerse the d re n of theelectric current in alternate, coils slsq that ;;the magnetic polarityreversed in alternate esii 'o is i. hs'ls m r t a l b: tained in otherways as by winding alternate I coils in opposite directions.

"In practice when the apparatusis in operatien 55 and the coils". 3'3.are electrically energized, the

cores 3 i'will be magnetized, the arrangement bing such that thesections 2') and c "of each core will be of the same magnetic polaritywhilefthe section" of base' plate "25 under core section a of 6()';};.8&Ch core will be of opposite magnetic'polarity; throughout theseries-the magnetic polarity of the core section'sc, band 0, inalternate cores 34- is reversed, so-that the core sections a, b and c ofone set-cf cores will respectively'corre- ;;spond with each other'inpolarity and the sections cab and c of .thegintermediate or othenset ofcores ,will respectively correspond with each other in opposite polaritywith regard to the core sections a, b and c respectively of thefirstsetof cores. Similarly the polarity of each pole shoe 33 will beopposite to the polarity of the cooperating angle plate 36 with which itis in spaced vertical registry.

In the operation of theapparatus which has netic coils allocated in therecessed portion 24, of the nonmagnetic part3 and ;surrounding thedescribing the novel separator, the cane which previously has beensubjected to the action of the customary revolving cane knives, ispassed between the crushing rollers II and 12 from which the mat ofcrushed cane, after traveling 5 over the magnetic separator, passesdownwardly along the chute 32 to the mill rolls l5 and from thencethrough the remaining portions of the apparatus until the particularprocess has been completed. During these operations the mag- 10 neticcoils 3'0 being electrically energized, part of the magnetic fluxgenerated in the sections a of the cores 36 passes through thebase-plate 25 to the pole shoes 33 thereof. As the polarity at the endof each coil is opposite, magnetic flux 15 of opposite polaritycoincidentally passes through the sections 1; and c of the cores 3 3 sothat the angle plates 36 which are in metallic engagement with thesections 0 are correspondingly magnetized'and accordingly are oppositein polarity to 20 the polarity of the pole shoes 33 with whichthey arerespectively in spaced vertical registry. As a result of this, magneticfields are developed between each; pole shoe 33 and the co-op'eratin'gangle plate '36 inspaced vertical registrythere-2 with, these magneticfields being relatively pow-'1 erful and being located outside andindependent; of the path of the travelling mat of,,cane or equivalentmoving body of other material- The magnetic flux which continuesupwardly through the sections b of the cores 34 radiates magnetic linesof'force between adjacent cores, which as previously stated are ofalternately reversed 'po. larity in said sections b; withthisarrangement open magnetic fields are thus created along'the :1:

guide member 2!] in the path; of travel of the mat of cane or equivalentbody of material and transversely to said path. Although the magneticpull is strongest directly over the sections 1) of thecores 34, theholding strength of the 40 magnetic fields are materially reduced by theintervening non-magnetic cover-plate. 2! which has been provided forthis purpose. As a're-t sultof this, any stray piecesof iron, steel or."

other substances contained in the mat of cane or equivalent materialwill merely be pulled downwardly throughthemat and held in contact withthe non-magnetic cover-plate 2i; in other words, the resulting magneticfields have a strength sufiicient to draw any magnetizable substancescontained in the traveling body of material to the surface of thecover-plate 2i but'insufiicient to prevent the movement of saidsubstances with said traveling body along said guide member.

' By the action of the downwardly moving mat of cane or equivalentmaterialas-it passes from the crushing rolls to the first mill, theaforesaid stray pieces of iron, steel or other substances areaccordingly carried downwardly toward the delivery edge of the guidemember 20, it being so g understood that this result may be accomplishedI with relatively little power becauseof the reduction of theholdingstrength of thestrong mag-.- netic fields due to the presence of thenon-magnetic cover-plate 29. The downward movement of the stray piecesof iron, steel or other substances over the non-magnetic cover-plate 2|is continued until the angle plates 36 are reached 1 which angle platesas previously stated are strongly .magnetized; fields are developedadjacent the delivery edge of the guide-member between theangle plates 736 and the pole shoes'33, the stray pieces of iron,

steelv or other substances being pushed. downwardly withthe movi g matof cane or equiva 1 Since strong magnetic 7 aosasralent: material willfinally be' completely with drawn from the. traveling mat or other bodyof material and caused to bridge'the magneticgaps between said angleplates 36 and the pole shoes 33;; the stray'pieces accordingly will bestronglyv and firmly held at these points-which are well outside ofthe'path of; the moving mat of cane onequivalent material. Such straypieces of iron;.

steel. or other. substances which may accumulate I at thexindicatedpoints outside'of the path of the mat of cane or equivalent materialinaybe periodically removed in anyeconvenient manner- .The scrapertip l9,the'lower portion of which extends into close proximity to the upwardly.extending sections 1) of the cores 34, if made of magnetic. materialbecomes strongly magnetized by induction. While this arrangement may bedesirable and preferred under certain conditions, it is not absolutelynecessary in order to effect the desired results. In other words, thescraper tip l9 may, if desired, be made of non-magnetic material inwhich case the magnetic flux expended in inducing magnetism in a scrapertip of magnetic material may be utilized to increase magnetic radiationor, in other words, to produce stronger magnetic fields over thenon-magnetic cover-plate 2|.

With the present arrangement when used in cane crushing apparatus as inthe illustrated example, the magnetic separator may be placed directlyadjacent to the crushing rolls so that the extraction of any straypieces of iron, steel or other substances is commenced directly as soonas the crushed cane leaves the crushing rolls H or H or theirequivalent. Injury to the mill rolls by such stray pieces is accordinglyguarded against and positively prevented.

The novel magnetic separator in all of its forms is of maximumefiiciency in operation and operates to first draw stray pieces of iron,steel or other substances towards the bottom of the traveling mat ofcane or its equivalent and then definitely removes such stray piecesfrom the mat to a point outside of the path of travel thereof, theextracted stray pieces of iron, steel or other substances being firmlyand securely {held outside of such path of travel until removed atconvenient periodic intervals. The lower crushing roll may be magnetizedin constructions where highly magnetized crushing rolls are in use andthus assist in the attraction of stray pieces of magnetizable materialand the conduction thereof between the crusher rolls to customary trampiron collectors, and the instant arrangement may be efiectively used incombination therewith; on the other hand the novel magnetic separator isequally well designed for efficient application to crushing rolls whichdue to their alloy composition become magnetized only to a negligibledegree or not at all.

While the magnetic separator herein shown and described contains sixcoils or electro-magnets, it is to be understood that this number may bediminished or increased in dependence upon the dimensions of the canecrushing or other apparatus and the thickness of the mat of sugar caneor equivalent material being treated therein.

Although the novel magnetic separator has been illustrated and describedas applied to a sugar cane mill, it is obvious as previously statedherein that it may be used in other types of machines and otherinstallations in which the prob- 2,.Various.-.changes in'the. specificforms shown and described may be made. within the scope of the-claimswithout departing from the spirit the. invention. 7

- 1. A magnetic separator comprising a recessed nonemagnetic supportingbar, an inclined nonmagnetioguide member for a traveling body ofmaterial carriedby said supporting bar, a magnetic base-plate secured tosaid bar, a non-magnetic..-:'coverplate located in surface engagementwithsaid guide-member and provided at intervals along itsslower edgewith recesses, magnetic.

anglepieces fitted over the lower edge of said guide-member and into therecess of said coverplate;.pole shoes-on said base-plate at intervals inspaced vertical registry with said angle pieces, and electro-magneticmeans mounted in said recessed supporting bar and including cores havingupright upper and lower sections and transverse horizontal sections, theupper sections hav ing their free end faces substantially in engagementwith said non-magnetic cover-plate, the lower sections engaging saidmagnetic base-plate,

and the horizontal sections engaging said magnetic angle pieces.

2. A magnetic separator comprising a recessed non-magnetic supportingbar, a non-magnetic guide member for a traveling body of materialcarried by said bar, a magnetic base-plate secured each having anothersection of opposite polarity in engagement with said baseplate, thepolarity being reversed in alternate cores, electro-magnetic coilssurrounding said cores for magnetizing the same, a non-magneticcover-plate located on the surface of said guide member and providedwith spaced recesses adjacent the delivery edge of said guide member,magnetic angle plates fitted into the recesses of said cover-plate andover the delivery edge of said guide member in contact with sections ofsaid cores, and pole shoes at spaced intervals on said base-plate inspaced vertical registry with said angle plates, each pole shoe and itsco-operating angle plate being of opposite polarity whereby magneticfields are created outside of the path of travel of said body oftraveling material for withdrawing magnetizable substances from saidmaterial and firmly holding the withdrawn substances outside of saidpath of travel of said body of material.

3. In a machine for crushing and treating sugar cane including a pair ofcrushing rolls and a mill in spaced relation thereto, that improvementwhich comprises a magnetic separator consisting of a scraper tip inengagement with the lower crushing roll, a non-magnetic guide membercarrying said scraper tip, the latter and said guide member extending ina downwardly inclined direction from said crushing roll toward said milland together serving to direct the traveling mat of cane from saidcrushing rolls toward said mill, a recessed non-magnetic supporting barcarrying said guide member, a magnetic base-plate secured to said bar, aplurality of magnetic cores arranged in spaced relation lengthwise ofsaid bar and each having sections of a given polarity terminatingsubstantially flush with the surface of said guide member intransversely spaced relation to each other, and each having anothersection of opposite polarity in engagement with said base-plate, thepolarity being reversed in alternate cores, electron-magnetic coilssurrounding said cores for magnetizing the same; a non-magneticcover-plate located on the surface or said guide member and coveringcorresponding sections of said cores whereby open magnetic fields arecreated along the surface of said guide member in the path of travel ofsaid mat of cane and transversely thereto, said open magnetic fieldshaving a strength sufi'icient to draw any magnetizable substancescontained in the mat of cane to the surface of said cover-plate butinsuflicient to prevent the movement of said substances with saidtraveling mat of cane toward said mill, said cover-plate being providedwith spaced recesses adjacent the delivery edge of said guide member,magnetic angle pieces fitted into the recesses of said cover-plate andover the delivery edge'of said guide member in contact with sections ofsaid cores, and pole shoes at spaced intervals on said base-plate inspaced vertical registry with said angle pieces, each pole shoe andco-operating angle piece being of opposite polarity whereby magneticfields are created adjacent the de- ERNEST GROSSEN'BACHER.

